The formula for calculating the focal coordinates is p/2. The trajectory to a point on the plane where a fixed point is equidistant from a fixed line is called a parabola, where the fixed point is called the focus of the parabola and the fixed line is called the directrix of the parabola. Focus coordinate and directrix equation are two main parameters of conic. In a plane, the trajectory to a point with the same distance from a fixed line is called parabola. The fixed point is called the focus of parabola, and the fixed line is called the directrix of parabola.

Parabolic focal coordinate formula

Definition of focus chord chord length formula of parabola in the field of geometry: If a straight line with inclination α passes through parabola focus F and intersects parabola at points A ... B, then the length of AB is 2P/(sinα)2 (that is, 2P divided by the square of sinα).

Hyperbolic focal coordinate formula

The focus is on the X axis (-c, 0) and (c, 0); The focus is on the y axis: (0, -c), (0, c). A hyperbola has two focal points, and the horizontal (vertical) coordinates of the focal points satisfy c = a+B. On the plane, the ratio of the distance from a given point to a straight line is a constant e (e((e >；; 1), that is, the eccentricity of hyperbola) is called hyperbola.

The focus is on the X axis (-c, 0) and (c, 0); The focus is on the y axis: (0, -c), (0, c). A hyperbola has two focal points, and the horizontal (vertical) coordinates of the focal points satisfy c = a+B. On the plane, the ratio of the distance from a given point to a straight line is a constant e (e((e >；; 1), that is, the eccentricity of hyperbola) is called hyperbola.

Elliptic focal coordinate formula

The coordinate formula of elliptical focal point is a 2-b 2 = c 2, where a is the length of major axis, b is the length of minor axis, and c is the focal length. If the long axis is on the X axis, the focal length is (c, 0), (-C, 0), and if the long axis is on the Y axis, the focal length is (0, c), (0, -C).

In mathematics, an ellipse is a trajectory in which the sum of the distances between two fixed points on a plane is constant. These two fixed points are called focal points.

Through this definition, draw an ellipse as follows: first, prepare a line and tie the two ends of this line to one point (these two points are regarded as the two focuses of the ellipse); Take a pen and tighten the thread. At this time, the two points and the pen form a triangle. Then pull the wire and start drawing, and keep the wire tight, and finally you can complete an oval shape.